INTRODUCTIONCommunity-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged worldwide. In contrast to healthcare-associated MRSA (HA-MRSA), CA-MRSA isolates are usually susceptible to multiple non-beta-lactam antibiotics and cause a distinct spectrum of infections in epidemiologically disparate populations - in particular, cutaneous abscesses, necrotising fasciitis and necrotising pneumonia. They arise from a broader genetic background, and possess differing virulence genes. We aim to describe the distribution of different molecular subtypes of CA-MRSA among various regions and discuss briefly the implications of CA-MRSA from a local perspective.

METHODSLiterature review of articles on CA-MRSA, focusing mainly on reports where the genetic background of isolates had been analysed using multi-locus sequence typing (MLST). Singapore data were obtained from the local CA-MRSA database.

RESULTSMLST analysis demonstrated the presence of epidemic subtypes of CA-MRSA within most geographic areas. In parts of the United States, community MRSA infections currently exceed those caused by their methicillin-susceptible counterparts. In Singapore, CA-MRSA infections are increasing, predominantly as a result of the spread of ST30 clones.

CONCLUSIONAvailable evidence suggests that the emergence of MRSA from the community is not going to be a transient phenomenon. Local guidelines for dealing with this phenomenon at both therapeutic and preventive levels are needed prior to the potential development of a situation mirroring that of meso-endemic HA-MRSA in local hospitals or CA-MRSA epidemics in parts of USA.

Bacterial Typing Techniques ; Community-Acquired Infections ; epidemiology ; microbiology ; Cross Infection ; diagnosis ; microbiology ; Humans ; Methicillin Resistance ; Risk Factors ; Singapore ; epidemiology ; Staphylococcal Infections ; epidemiology ; microbiology ; Staphylococcus aureus ; classification ; drug effects

COVID-19/prevention & control* ; COVID-19 Vaccines ; Health Personnel ; Humans ; Singapore ; Vaccination

INTRODUCTIONImipenem and meropenem are treatment of choice for extended-spectrum betalactamase (ESBL)-positive gram-negative bacteraemia. They may select for carbapenemresistant Acinetobacter baumannii and Pseudomonas aeruginosa; ertapenem may not do so as it is inactive against these bacteria. Clinical efficacy of ertapenem in ESBL-producing gramnegative bacteraemia is limited.

MATERIALS AND METHODSRetrospective study of patients with ESBL-positive gram-negative bacteraemia treated with ertapenem was undertaken.

RESULTSForty-seven patients with multidrug-resistant gram-negative bacteraemia (79% produced ESBL) were treated with ertapenem for a median duration of 11 days. The median age was 70 years. Septic shock occurred in 19% and mechanical ventilation was needed in 17%. Klebsiella pneumoniae comprised 53% and Escherichia coli 26%. Urinary infection accounted for 61% and hepatobiliary 15%. Favourable clinical response occurred in 96%. Attributable mortality was 4%.

CONCLUSIONErtapenem is promising in culture-guided step-down therapy of ESBL-positive gram-negative bacteraemia.

Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Bacteremia ; drug therapy ; etiology ; Drug Resistance, Multiple, Bacterial ; Escherichia coli ; drug effects ; enzymology ; Escherichia coli Infections ; drug therapy ; microbiology ; Female ; Gram-Negative Bacteria ; drug effects ; enzymology ; Gram-Negative Bacterial Infections ; drug therapy ; microbiology ; Humans ; Klebsiella Infections ; drug therapy ; microbiology ; Klebsiella pneumoniae ; drug effects ; enzymology ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Retrospective Studies ; Urinary Tract Infections ; complications ; drug therapy ; beta-Lactamases ; biosynthesis ; beta-Lactams ; pharmacology ; therapeutic use